Class: RubyCan::CanSocket

Inherits:
Socket
  • Object
show all
Defined in:
lib/ruby_can/can_socket.rb

Constant Summary collapse

PF_CAN = 
29
AF_CAN = 
PF_CAN
CAN_RAW = 
1
SIOCGIFINDEX = 
0x8933

Instance Method Summary collapse

Constructor Details

#initialize(can_interface_name) ⇒ CanSocket

Returns a new instance of CanSocket.



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# File 'lib/ruby_can/can_socket.rb', line 11

def initialize( can_interface_name )
  
  super(PF_CAN, Socket::SOCK_RAW, CAN_RAW)
  
  # struct ifreq in net/if.h
  if_idx_req = can_interface_name.ljust(16,"\0")+[0].pack("L")
  ioctl(SIOCGIFINDEX, if_idx_req )
  
  if_name,if_index = if_idx_req.unpack("A16L")
  
  # sockaddr_can from linux/can.h
  #struct sockaddr_can {
  #  __kernel_sa_family_t can_family;                                     S
  #  int         can_ifindex;                                             l
  #  union {
  #    /* transport protocol class address information (e.g. ISOTP) */
  #    struct { canid_t rx_id, tx_id; } tp;                               LL
  #
  #    /* reserved for future CAN protocols address information */
  #  } can_addr;
  #};
  # align on 16 byte -> pad with 2 bytes exta                             S
  
  sockaddr_can = [AF_CAN,if_index,0,0,0].pack("SlLLS")
  
  bind(sockaddr_can)
end